1. Field of the Invention
The present invention relates to a magnetic attraction preventive system which prevents magnetic attraction of a magnetic material to a magnetic resonance imaging apparatus which results from a magnetic field generated from the apparatus.
2. Description of the Related Art
A magnetic field generated by a magnetic resonance imaging apparatus extends to the outside of it. For this reason, so-called magnetic attraction can occur in which a magnetic material is attracted to the magnetic resonance imaging apparatus by the magnetic field.
In recent years, the magnetic fields generated by magnetic resonance imaging apparatuses have been much increased in strength. For this reason, a large object can be attracted to the apparatus or the moving speed of an object being attracted can increase. The collision of the object with the magnetic resonance imaging apparatus may cause or threaten damage to the object or the apparatus.
In view of such circumstances, in the rules of use of magnetic resonance imaging apparatus, it is laid down not to bring a magnetic material close to the apparatus. However, it is said that human errors will occur at a probability of 3×10−3. It is therefore impossible to perfectly remove human errors. Therefore, relying on only the attention of human beings involves difficulties in preventing magnetic attraction sufficiently
A technique to reduce leakage magnetic fields is disclosed in, for example, JP-A 2004-350888 (KOKAI).